This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A364308 #20 Oct 01 2024 03:33:18
%S A364308 644,740,804,986,1034,1064,1104,1220,1274,1308,1309,1462,1494,1580,
%T A364308 1748,1884,1885,1924,1988,2013,2014,2108,2134,2254,2288,2294,2330,
%U A364308 2354,2364,2408,2464,2484,2540,2583,2584,2664,2665,2666,2678,2684,2714,2715,2716,2754,2793
%N A364308 Numbers k such that k, k+1 and k+2 have exactly 3 distinct prime factors.
%H A364308 David A. Corneth, <a href="/A364308/b364308.txt">Table of n, a(n) for n = 1..10000</a>
%F A364308 a(1) = A080569(3).
%F A364308 {k: A001221(k) = A001221(k+1) = A001221(k+2) = 3}.
%e A364308 644 = 2^2*7*23 has 3 distinct prime factors, 645 = 3*5*43 has 3 distinct prime factors, and 646 = 2*17*19 has 3 distinct prime factors, so 644 is in the sequence.
%t A364308 q[n_] := q[n] = PrimeNu[n] == 3; Select[Range[3000], q[#] && q[#+1] && q[#+2] &] (* _Amiram Eldar_, Oct 01 2024 *)
%Y A364308 Subsequence of A006073 and of A140077.
%Y A364308 Cf. A364307 (2 factors), A364309 (4 factors), A364266 (5 factors), A364265 (6 factors), A001221, A080569.
%K A364308 nonn
%O A364308 1,1
%A A364308 _R. J. Mathar_, Jul 18 2023